The applicant requests $747,560 in direct costs over a period of four years to study the development of males' intimate relationships with the opposite sex; she will add a new set of data components to a well-established longitudinal study of at risk boys, (the Oregon Youth Study (OYS). This multimethod/multiagent study began with two cohorts of boys in grade four (total N=206) who are now 17 to 19 years of age. The study has a 96.6 percent retention rate. The application examines the effect of the young man's prior personality and family experience on mate selection and the quality of his intimate relationship with a dating or live- in partner. The understanding of conflictful and dysfunctional intimate relationships in early adulthood is important because these relationships affect individuals' subsequent life trajectory; they are a major source of unhappiness and depression and may lead to family breakdown in the next generation. Assessment measures in the new data-gathering phases include self-report instruments from both partners and observations based on a videotaped interaction task. In this re-submission, a central focus is on physical and emotional abuse within the relationship. In addition to interaction behaviors, measures to be obtained include antisocial behavior, depression, self-esteem, academic achievement and substance use in both partners. A basic assumption to be tested in this proposed study is that individuals choose environments that are compatible with their own dispositions and prefer to affiliate with people similar to themselves. Origins of prosocial intimate relationships will be examined as will alternative pathways from risk status to positive outcomes (primarily through pairing with a prosocial, interpersonally skilled partner). Models of developmental changes in relationships from age 17-19 to age 20-21 will also be tested.